1. Technical Field
This invention generally relates to regulators, and more specifically relates to a torque isolation system for use in regulators.
2. Background Art
Tagout procedures for valves and other types of regulators are required when an individual must leave a valve or regulator, but the valve or regulator must remain open, closed, or partially open for safety reasons. The procedures require the individual to leave a "tag" on the regulator indicating that others should not tamper with the regulator in the individual's absence. Tags must be attached to the regulator in a conspicuous manner so that others will recognize the tag and avoid tampering with the valve or regulator.
In lockout-tagout procedures, a user locks the regulator in a set position to prevent its actuation, and places a tag on it as in tagout procedures. Although tagout procedures are usually effective, lockout-tagout procedures provide additional safety by preventing actuation of the regulator. Moreover, OSHA regulations do not require training of employees to be as extensive for lockout-tagout procedures as for tagout procedures alone. By using lockout-tagout procedures rather than tagout procedures alone, employers can avoid the costs and disruptions to normal business that result from extensive training requirements.
Prior lockout devices have not been convenient to use. One example of such a device is a shell that covers the regulator handle. By covering the handle, the shell prevents actuation of the regulator. Accordingly, if the regulator is partially open, the shell will prevent it from being further opened or further closed. Such a shell does not allow the regulator to be closed, while preventing it from being opened at the same time. Also, the shell cannot be used on regulators that are in tight spaces, such as regulators used in the microelectronics industry, or on regulators with large handles.
Other valves have lockout devices, such as those described in U.S. Pat. No. 4,881,388 to Pruim and U.S. Pat. No. 1,545,712 to Toy, that are locked and unlocked using a single key. Such lockout devices are not useful in lockout-tagout procedures. In lockout-tagout procedures the user who locks the regulator should be the only one who can unlock the regulator. If all users have the same key, then any user can unlock the regulator.